High price of 600 amp circuit breakers?

According to Ignoramus5533 :

They're basically relatively low demand things used commercially/industrially, and they're much more rugged than their residential counterparts.

It takes good design to reliably interrupt a 400-600A circuit without blowing up the neighborhood. Especially at higher voltages.

If you think that's bad, you should see the breakers they have to use with higher ampacities and voltages. "air blast arc suppression" etc. I'm glad we don't have to do that at a mere

15A ;-)

Bigger frame breakers have always cost a lot more. Larger frame breakers are can be made to withstand larger fault currents. Interrupt larger current at higher voltages. I used to work for an OEM and we had some circuit breakers that were well over $25000.00 (SPB series) "rebuilt". New more like $40k.

I have installed some medium voltage vacuum breakers that were well over $100k each.

Unfortunately they are just so much boat anchor material unless you have a need for one of them. They are not interchangeable. There is a thriving market in rebuilding, testing and installing such equipment.

OK.

Sure, I agree.

What you are saying, in other words, is that their price reflects not only the production costs, but also costs of R&D etc, spread out among relatively few produced pieces. Hence the cost.

Right?

Some of the new breakers somewhat similar to mine have a MSRP of $11,666!!!

i

I see. That makes sense....

i

I would understand that, for vacuum units.

I am not sure about interchangeability. My 400-600 A breakers (Siemens, ITE, Westinghouse etc) simply take 3 wires in and 3 wires going out. They do not mount on special connector panels, like residential breakers.

i

My experience in refining precious metals taught me that high amperage contacts are usually made from a compound of silver and some other element, often tungsten. You can expect the breakers to contain silver, but that hardly explains the high cost, particularly when a contact is generally well under a troy ounce in size. Cost is likely attributed to a high degree of engineering and limited production.

That's my story, and I'm stickin' too it!

Harold

According to Ignoramus5533 :

Right. Remember also that these things tend to be multiple pole breakers too. So, trying to see some relationship in cost between one of these beasties and a single slot 15A residential breaker is bound to fail ;-)

I got it. Thanks Chris, Harold, SQLit.

I have a related question. I want to sell them on ebay and would like to get as much as I can. The obvious things I can do is wipe the dust, photograph them very well and test them with an ohm meter. Is there anything else, something unobvious, that I could do?

thanks, as always.

i

According to Ignoramus5533 :

Check for cracks, corrosion or pitting on the connectors. Ensure that the contacts open/close when you operate the handle.

If you can see/get at the contacts, check them for heavy pitting. [Sometimes these things have replaceable contacts, so you may be able to get at them.]

Beyond that, you'd need to test them to see if they trip for overcurrent. This is absolutely _not_ something you can test short of having a purpose built lab with a lot of very expensive gear, least of which being a power supply that can deliver one heck of a lot of amps. And a shorting switch that won't explode at, say, 100,000 amps.

Thank you. all good ideas.

I agree. I could use some welding cables and several car batteries, and use large steel flats for switching, but I do not see the point and it is just too dangerous.

Checking the contacts is a great idea.

i

At one time they contained cadmium as well as sliver. The guy I used to work with at GTE Labs was working on replacing the cad with, among other things, Wo.

Anyone taking older breakers like that apart should be alert for cadmium in the items, including that which was vaporized and sprayed around inside the housing.

Jim

In addition to the low demand and cost of engineering, another thing that probably inflates the cost is reliability testing. Very often the same product is labeled and sold at different prices, the primary difference being the amount of testing that went into ensuring the reliability of the device. A good example is the difference between military and commercial electronic parts.

In your case, you cannot guarantee reliability, provide a warrantee or perhaps even guarantee functionality and this will all substantially reduce the price for an eBay customer. Good luck, I find that electronic parts sell slowly on eBay. Look at the number of bids on those parts for a preview. Stuff is only worth what someone will pay for it, fortunately you paid nothing. I think you will do better with a return if DOA policy rather than an AS-IS policy.

Fair enough.

Try search ebay for:

"400 amp" circuit breaker -(new) "600 amp" circuit breaker -(new)

(cut and paste this into the search box)

You would find that these breakers briskly sell for about $150-230, with the average price of about $190-200 or so.

If you look closely at ebay histories of auction winners, you would see that they are professional dealers of circuit breakers. What I suspect they do, is buy these breakers on ebay, test them, perhaps replace contacts or whatever, call them "FACTORY RECONDITIONED" and resell to their own customers for a few times more than what they paid.

Thusly, I am leaning towards selling all these breakers in one lot, to save shipping to such buyers. I would prefer selling to these professionals instead of dealing with clueless individual buyers who buy them to use at their locations.

i

Send an email to these pro dealers (eBay sellers) and ask if they would like to buy your lot directlly from you. You may not get the max price but you won't have to wait through several unsuccessful auctions (assuming you use a minimum price) or get lowballed cause there is another just like it this week etc.

Thanks. My thinking was that these sellers would have an informational advantage over me (they know more than I do) and I would not get what I could get for them, if I offered them privately. They know what these breakers are. If I listed them on ebay as one lot with 10-11 breakers in the lot (forgot how many I have in fact), they they would at least bid against one another, and that would reduce my disadvantage.

i

Those sound like the "universal or OEM" mounts. Almost everyone makes those in some form.

Yes, that's right. I could screw them to any metal sheet, it seems. I will double check tonight, they are still in my pickup.

i

Well, you could just get a 1000A breaker and a greater-than-1000A power supply and then test with the 1000A breaker "up the line". That way his shorting switch only needs to be able to handle 1000A since if his 600A breaker *doesn't* trip he'd only need to be able to handle 1000A at the shorting switch. Right?

I'm not even sure that would work. I think the ratings on these things take the voltage into account, too...

--Donnie

Speaking of which, check out this very cool site:

In particular, check out the two (large) videos of the HV disconnect switches opening hot. Very exciting!

You may also be fascinated by the coin shrinking tricks elsewhere on the author's site.

- Michael